In various current techniques for diagnosing chest or brain tumors, diffusion optical tomography (DOT) has become a popular method for its non-intrusiveness and real-time imaging.
Specifically, diffusion optical tomography utilizes the fact that body tissues or tumors exhibit different optical properties (e.g. absorption, reflection and deflection) to excitation light with specific wavelengths and thus the differences in tissues and inner structure of the human body can be identified. For example, oxygenated and non-oxygenated hemoglobin have different levels of absorption to near-infrared light. Therefore, such characteristics can be used in clinic trials related to blood flow, blood volume and oxygen saturation concentration, and also for determination of body tissues or tumors as just mentioned. Thus, the use of near-infrared light in diffusion optical tomography creates more benefits and extends the application range of the diffusion optical tomography.
In recent years, along with research developments and advances in manufacturing technologies, diffusion optical tomography enables quick operations on the results of image reconstruction, so diagnosis becomes safe and reliable. However, existing diffusion optical tomography is usually realized by large-size machine, which occupies large space and increases power consumption. In particular, circuits for emitting near-infrared light or for detecting optical signals returned by the human tissues or tumors often include a plurality of light sources or sensors so as to emit more light or sense more optical signals. The arrangements for these light sources and sensors are complex, and it is difficult to achieve good detection in limited circuit space.
Moreover, as for the image reconstruction technique used after diffusion optical tomography, in order to meet the requirement for high image resolution, extremely large matrix operations often have to be performed on the tomography results. However, huge matrix operations often results in long imaging time and a bulky system, and real-time scanning and real-time imaging cannot be realized.